Malaria Genomes Pose New Challenges

Two malaria genomes sequenced by international research teams have yielded information on genetic variability that is expected to aid in developing new drugs and vaccines to wipe out the disease—but not without posing additional challenges.

A pair of studies published in the journal Nature Genetics focused on Plasmodium vivax (P. vivax), the most prevalent human malaria parasite outside Africa and a malaria species that afflicts humans; and Plasmodium cynomolgi (P. cynomolgi), which infects Asian Old World monkeys and is closely related to P. vivax.

“The bad news is there is significantly more genetic variation in P. vivax than we’d thought, which could make it quite adept at evading whatever arsenal of drugs and vaccines we throw at it,” Jane Carlton, Ph.D., of New York University’s Center for Genomics and Systems Biology, the senior author on both studies, said in a statement.

“However, now that we have a better understanding of the challenges we face, we can move forward with a deeper analysis of its genomic variation in pursuing more effective remedies,” added Dr. Carlton, who is the center’s faculty director of genomic sequencing.

In the P. vivax study, which offered the first genome-wide perspective of global variability within the species, researchers found that it has twice as much genetic diversity as the worldwide Plasmodium falciparum (P. falciparum) strains, revealing an unexpected ability to evolve and, therefore, presenting new challenges in the search for treatments.

The second study entailed researchers joining with Kazuyuki Tanabe, D.Sci., D.Med.Sci., SA Professor at Japan’s Osaka University to sequence three genomes of P. cynomolgi, then comparing its genetic make-up to P. vivax and to a previously sequenced malaria parasite affecting both monkeys and humans in parts of Southeast Asia, Plasmodium knowlesi (P. knowlesi).

That study marked the first time P. cynomolgi genomes have been sequenced, allowing researchers to identify genetic diversity in the parasite. Its similarity to P. vivax means that results from that study are also likely to benefit future efforts to understand and fight against forms of malaria that afflict humans, Dr. Tanabe and the team concluded.

“We have generated a genetic map of P. cynomolgi, the sister species to P. vivax, so we can now push forward in creating a robust model system to study P. vivax,” Dr. Tanabe said in the statement, adding that a model was desperately needed because P. vivax cannot be grown in a lab.